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no changes needed (XFS isn't simple, but it has the same parallelism
in the interesting parts exercised from CXFS).
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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no need to lock directory in dcache_dir_lseek(), while we are
at it - per-struct file exclusion is enough.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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Switch dcache pre-seeding on readdir to d_alloc_parallel();
nothing else is needed.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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make it usable with directory locked shared
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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... making it usable with directory locked shared
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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New method: ->iterate_shared(). Same arguments as in ->iterate(),
called with the directory locked only shared. Once all filesystems
switch, the old one will be gone.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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same as read() on regular files has, and for the same reason.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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ta-da!
The main issue is the lack of down_write_killable(), so the places
like readdir.c switched to plain inode_lock(); once killable
variants of rwsem primitives appear, that'll be dealt with.
lockdep side also might need more work
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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If we *do* run into an in-lookup match, we need to wait for it to
cease being in-lookup. Fortunately, we do have unused space in
in-lookup dentries - d_lru is never looked at until it stops being
in-lookup.
So we can stash a pointer to wait_queue_head from stack frame of
the caller of ->lookup(). Some precautions are needed while
waiting, but it's not that hard - we do hold a reference to dentry
we are waiting for, so it can't go away. If it's found to be
in-lookup the wait_queue_head is still alive and will remain so
at least while ->d_lock is held. Moreover, the condition we
are waiting for becomes true at the same point where everything
on that wq gets woken up, so we can just add ourselves to the
queue once.
d_alloc_parallel() gets a pointer to wait_queue_head_t from its
caller; lookup_slow() adjusted, d_add_ci() taught to use
d_alloc_parallel() if the dentry passed to it happens to be
in-lookup one (i.e. if it's been called from the parallel lookup).
That's pretty much it - all that remains is to switch ->i_mutex
to rwsem and have lookup_slow() take it shared.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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We will need to be able to check if there is an in-lookup
dentry with matching parent/name. Right now it's impossible,
but as soon as start locking directories shared such beasts
will appear.
Add a secondary hash for locating those. Hash chains go through
the same space where d_alias will be once it's not in-lookup anymore.
Search is done under the same bitlock we use for modifications -
with the primary hash we can rely on d_rehash() into the wrong
chain being the worst that could happen, but here the pointers are
buggered once it's removed from the chain. On the other hand,
the chains are not going to be long and normally we'll end up
adding to the chain anyway. That allows us to avoid bothering with
->d_lock when doing the comparisons - everything is stable until
removed from chain.
New helper: d_alloc_parallel(). Right now it allocates, verifies
that no hashed and in-lookup matches exist and adds to in-lookup
hash.
Returns ERR_PTR() for error, hashed match (in the unlikely case it's
been found) or new dentry. In-lookup matches trigger BUG() for
now; that will change in the next commit when we introduce waiting
for ongoing lookup to finish. Note that in-lookup matches won't be
possible until we actually go for shared locking.
lookup_slow() switched to use of d_alloc_parallel().
Again, these commits are separated only for making it easier to
review. All this machinery will start doing something useful only
when we go for shared locking; it's just that the combination is
too large for my taste.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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We'll need to verify that there's neither a hashed nor in-lookup
dentry with desired parent/name before adding to in-lookup set.
One possible solution would be to hold the parent's ->d_lock through
both checks, but while the in-lookup set is relatively small at any
time, dcache is not. And holding the parent's ->d_lock through
something like __d_lookup_rcu() would suck too badly.
So we leave the parent's ->d_lock alone, which means that we watch
out for the following scenario:
* we verify that there's no hashed match
* existing in-lookup match gets hashed by another process
* we verify that there's no in-lookup matches and decide
that everything's fine.
Solution: per-directory kinda-sorta seqlock, bumped around the times
we hash something that used to be in-lookup or move (and hash)
something in place of in-lookup. Then the above would turn into
* read the counter
* do dcache lookup
* if no matches found, check for in-lookup matches
* if there had been none of those either, check if the
counter has changed; repeat if it has.
The "kinda-sorta" part is due to the fact that we don't have much spare
space in inode. There is a spare word (shared with i_bdev/i_cdev/i_pipe),
so the counter part is not a problem, but spinlock is a different story.
We could use the parent's ->d_lock, and it would be less painful in
terms of contention, for __d_add() it would be rather inconvenient to
grab; we could do that (using lock_parent()), but...
Fortunately, we can get serialization on the counter itself, and it
might be a good idea in general; we can use cmpxchg() in a loop to
get from even to odd and smp_store_release() from odd to even.
This commit adds the counter and updating logics; the readers will be
added in the next commit.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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marked as such when (would be) parallel lookup is about to pass them
to actual ->lookup(); unmarked when
* __d_add() is about to make it hashed, positive or not.
* __d_move() (from d_splice_alias(), directly or via
__d_unalias()) puts a preexisting dentry in its place
* in caller of ->lookup() if it has escaped all of the
above. Bug (WARN_ON, actually) if it reaches the final dput()
or d_instantiate() while still marked such.
As the result, we are guaranteed that for as long as the flag is
set, dentry will
* remain negative unhashed with positive refcount
* never have its ->d_alias looked at
* never have its ->d_lru looked at
* never have its ->d_parent and ->d_name changed
Right now we have at most one such for any given parent directory.
With parallel lookups that restriction will weaken to
* only exist when parent is locked shared
* at most one with given (parent,name) pair (comparison of
names is according to ->d_compare())
* only exist when there's no hashed dentry with the same
(parent,name)
Transition will take the next several commits; unfortunately, we'll
only be able to switch to rwsem at the end of this series. The
reason for not making it a single patch is to simplify review.
New primitives: d_in_lookup() (a predicate checking if dentry is in
the in-lookup state) and d_lookup_done() (tells the system that
we are done with lookup and if it's still marked as in-lookup, it
should cease to be such).
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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will be needed as soon as lookups are not serialized by ->i_mutex
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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Right now ext2_get_page() (and its analogues in a bunch of other filesystems)
relies upon the directory being locked - the way it sets and tests Checked and
Error bits would be racy without that. Switch to a slightly different scheme,
_not_ setting Checked in case of failure. That way the logics becomes
if Checked => OK
else if Error => fail
else if !validate => fail
else => OK
with validation setting Checked or Error on success and failure resp. and
returning which one had happened. Equivalent to the current logics, but unlike
the current logics not sensitive to the order of set_bit, test_bit getting
reordered by CPU, etc.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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... and explain the non-obvious logics in case when lookup yields
a different dentry.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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... and have it use inode_lock()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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grab a reference to dentry we'd got the sucker from, and return
that dentry via *wait, rather than just returning the address of
->i_mutex.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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... and do not assume they are already attached to each other
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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This reverts commit 1028b55bafb7611dda1d8fed2aeca16a436b7dff.
It's broken: it makes ext4 return an error at an invalid point, causing
the readdir wrappers to write the the position of the last successful
directory entry into the position field, which means that the next
readdir will now return that last successful entry _again_.
You can only return fatal errors (that terminate the readdir directory
walk) from within the filesystem readdir functions, the "normal" errors
(that happen when the readdir buffer fills up, for example) happen in
the iterorator where we know the position of the actual failing entry.
I do have a very different patch that does the "signal_pending()"
handling inside the iterator function where it is allowable, but while
that one passes all the sanity checks, I screwed up something like four
times while emailing it out, so I'm not going to commit it today.
So my track record is not good enough, and the stars will have to align
better before that one gets committed. And it would be good to get some
review too, of course, since celestial alignments are always an iffy
debugging model.
IOW, let's just revert the commit that caused the problem for now.
Reported-by: Greg Thelen <gthelen@google.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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reiserfs_xattr_[sg]et() will fail with -EOPNOTSUPP for V1 inodes anyway,
and all reiserfs instances of ->[sg]et() call it and so does ->set_acl().
Checks for name length in the instances had been bogus; they should've
been "bugger off if it's _exactly_ the prefix" (as generic would
do on its own) and not "bugger off if it's shorter than the prefix" -
that can't happen.
xattr_full_name() is needed to adjust for the fact that generic instances
will skip the prefix in the name passed to ->[gs]et(); reiserfs homegrown
analogues didn't.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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none of that stuff can ever be called for NULL or negative
dentry.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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... and neither can ever be NULL
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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Make sure we avoid a division-by-zero OOPS in case clock-frequency is
set too low in DT. Add missing '\n' while we are here.
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Acked-by: Axel Lin <axel.lin@ingics.com>
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This reverts commit 34cf2acdafaa31a13821e45de5ee896adcd307b1. 'ret' is
not set when bailing out. Also, there is a better place to check for 0.
Reported-by: Axel Lin <axel.lin@ingics.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
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I moderate these (lightly loaded) lists to block spam.
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Update the comment to reflect the changes of commit 0de7985 (parisc: Use
generic extable search and sort routines).
Signed-off-by: Helge Deller <deller@gmx.de>
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Handling exceptions from modules never worked on parisc.
It was just masked by the fact that exceptions from modules
don't happen during normal use.
When a module triggers an exception in get_user() we need to load the
main kernel dp value before accessing the exception_data structure, and
afterwards restore the original dp value of the module on exit.
Noticed-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Helge Deller <deller@gmx.de>
Cc: stable@vger.kernel.org
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The kernel module testcase (lib/test_user_copy.c) exhibited a kernel
crash on parisc if the parameters for copy_from_user were reversed
("illegal reversed copy_to_user" testcase).
Fix this potential crash by checking the fault handler if the faulting
address is in the exception table.
Signed-off-by: Helge Deller <deller@gmx.de>
Cc: stable@vger.kernel.org
Cc: Kees Cook <keescook@chromium.org>
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We want to avoid the kernel module loader to create function pointers
for the kernel fixup routines of get_user() and put_user(). Changing
the external reference from function type to int type fixes this.
This unbreaks exception handling for get_user() and put_user() when
called from a kernel module.
Signed-off-by: Helge Deller <deller@gmx.de>
Cc: stable@vger.kernel.org
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Commit 0de7985 (parisc: Use generic extable search and sort routines)
changed the exception tables to use 32bit relative offsets.
This patch now adds support to the kernel module loader to handle such
R_PARISC_PCREL32 relocations for 32- and 64-bit modules.
Signed-off-by: Helge Deller <deller@gmx.de>
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After commit f84bb1eac027 ("net: fix IFF_NO_QUEUE for drivers using
alloc_netdev"), default qdisc was changed to noqueue because
tuntap does not set tx_queue_len during .setup(). This patch restores
default qdisc by setting tx_queue_len in tun_setup().
Fixes: f84bb1eac027 ("net: fix IFF_NO_QUEUE for drivers using alloc_netdev")
Cc: Phil Sutter <phil@nwl.cc>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Signed-off-by: Martin Brandenburg <martin@omnibond.com>
Signed-off-by: Mike Marshall <hubcap@omnibond.com>
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Emit the logging messages at the appropriate levels.
Miscellanea:
o Change format to fmt
o Use the more common ##__VA_ARGS__
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Mike Marshall <hubcap@omnibond.com>
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It would have been possible for a rogue client-core to send in a symlink
target which is not NUL terminated. This returns EIO if the client-core
gives us corrupt data.
Leave debugfs and superblock code as is for now.
Other dcache.c and namei.c strncpy instances are safe because
ORANGEFS_NAME_MAX = NAME_MAX + 1; there is always enough space for a
name plus a NUL byte.
Signed-off-by: Martin Brandenburg <martin@omnibond.com>
Signed-off-by: Mike Marshall <hubcap@omnibond.com>
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The ctime and mtime are always updated on a successful ftruncate and
only updated on a successful truncate where the size changed.
We handle the ``if the size changed'' bit.
This matches FUSE's behavior.
Signed-off-by: Martin Brandenburg <martin@omnibond.com>
Signed-off-by: Mike Marshall <hubcap@omnibond.com>
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fs/orangefs/orangefs-debugfs.c:130:2-26: WARNING: NULL check before freeing functions like kfree, debugfs_remove, debugfs_remove_recursive or usb_free_urb is not needed. Maybe consider reorganizing relevant code to avoid passing NULL values.
NULL check before some freeing functions is not needed.
Based on checkpatch warning
"kfree(NULL) is safe this check is probably not required"
and kfreeaddr.cocci by Julia Lawall.
Generated by: scripts/coccinelle/free/ifnullfree.cocci
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Mike Marshall <hubcap@omnibond.com>
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Suggested by David Binderman <dcb314@hotmail.com>
The former can potentially be a performance win over the latter.
memcpy(d, s, len);
memset(d+len, c, size-len);
memset(d, c, size);
memcpy(d, s, len);
Signed-off-by: Mike Marshall <hubcap@omnibond.com>
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1. It is nonsense to test for negative size_t, suggested by
David Binderman <dcb314@hotmail.com>
2. By the time Orangefs gets called, the vfs has ensured that
name != NULL, and that buffer and size are sane.
Signed-off-by: Mike Marshall <hubcap@omnibond.com>
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find_outdev calls inet{,6}_fib_lookup_dev() or dev_get_by_index() to
find the output device. In case of an error, inet{,6}_fib_lookup_dev()
returns error pointer and dev_get_by_index() returns NULL. But the function
only checks for NULL and thus can end up calling dev_put on an ERR_PTR.
This patch adds an additional check for err ptr after the NULL check.
Before: Trying to add an mpls route with no oif from user, no available
path to 10.1.1.8 and no default route:
$ip -f mpls route add 100 as 200 via inet 10.1.1.8
[ 822.337195] BUG: unable to handle kernel NULL pointer dereference at
00000000000003a3
[ 822.340033] IP: [<ffffffff8148781e>] mpls_nh_assign_dev+0x10b/0x182
[ 822.340033] PGD 1db38067 PUD 1de9e067 PMD 0
[ 822.340033] Oops: 0000 [#1] SMP
[ 822.340033] Modules linked in:
[ 822.340033] CPU: 0 PID: 11148 Comm: ip Not tainted 4.5.0-rc7+ #54
[ 822.340033] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996),
BIOS rel-1.7.5.1-0-g8936dbb-20141113_115728-nilsson.home.kraxel.org
04/01/2014
[ 822.340033] task: ffff88001db82580 ti: ffff88001dad4000 task.ti:
ffff88001dad4000
[ 822.340033] RIP: 0010:[<ffffffff8148781e>] [<ffffffff8148781e>]
mpls_nh_assign_dev+0x10b/0x182
[ 822.340033] RSP: 0018:ffff88001dad7a88 EFLAGS: 00010282
[ 822.340033] RAX: ffffffffffffff9b RBX: ffffffffffffff9b RCX:
0000000000000002
[ 822.340033] RDX: 00000000ffffff9b RSI: 0000000000000008 RDI:
0000000000000000
[ 822.340033] RBP: ffff88001ddc9ea0 R08: ffff88001e9f1768 R09:
0000000000000000
[ 822.340033] R10: ffff88001d9c1100 R11: ffff88001e3c89f0 R12:
ffffffff8187e0c0
[ 822.340033] R13: ffffffff8187e0c0 R14: ffff88001ddc9e80 R15:
0000000000000004
[ 822.340033] FS: 00007ff9ed798700(0000) GS:ffff88001fc00000(0000)
knlGS:0000000000000000
[ 822.340033] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 822.340033] CR2: 00000000000003a3 CR3: 000000001de89000 CR4:
00000000000006f0
[ 822.340033] Stack:
[ 822.340033] 0000000000000000 0000000100000000 0000000000000000
0000000000000000
[ 822.340033] 0000000000000000 0801010a00000000 0000000000000000
0000000000000000
[ 822.340033] 0000000000000004 ffffffff8148749b ffffffff8187e0c0
000000000000001c
[ 822.340033] Call Trace:
[ 822.340033] [<ffffffff8148749b>] ? mpls_rt_alloc+0x2b/0x3e
[ 822.340033] [<ffffffff81488e66>] ? mpls_rtm_newroute+0x358/0x3e2
[ 822.340033] [<ffffffff810e7bbc>] ? get_page+0x5/0xa
[ 822.340033] [<ffffffff813b7d94>] ? rtnetlink_rcv_msg+0x17e/0x191
[ 822.340033] [<ffffffff8111794e>] ? __kmalloc_track_caller+0x8c/0x9e
[ 822.340033] [<ffffffff813c9393>] ?
rht_key_hashfn.isra.20.constprop.57+0x14/0x1f
[ 822.340033] [<ffffffff813b7c16>] ? __rtnl_unlock+0xc/0xc
[ 822.340033] [<ffffffff813cb794>] ? netlink_rcv_skb+0x36/0x82
[ 822.340033] [<ffffffff813b4507>] ? rtnetlink_rcv+0x1f/0x28
[ 822.340033] [<ffffffff813cb2b1>] ? netlink_unicast+0x106/0x189
[ 822.340033] [<ffffffff813cb5b3>] ? netlink_sendmsg+0x27f/0x2c8
[ 822.340033] [<ffffffff81392ede>] ? sock_sendmsg_nosec+0x10/0x1b
[ 822.340033] [<ffffffff81393df1>] ? ___sys_sendmsg+0x182/0x1e3
[ 822.340033] [<ffffffff810e4f35>] ?
__alloc_pages_nodemask+0x11c/0x1e4
[ 822.340033] [<ffffffff8110619c>] ? PageAnon+0x5/0xd
[ 822.340033] [<ffffffff811062fe>] ? __page_set_anon_rmap+0x45/0x52
[ 822.340033] [<ffffffff810e7bbc>] ? get_page+0x5/0xa
[ 822.340033] [<ffffffff810e85ab>] ? __lru_cache_add+0x1a/0x3a
[ 822.340033] [<ffffffff81087ea9>] ? current_kernel_time64+0x9/0x30
[ 822.340033] [<ffffffff813940c4>] ? __sys_sendmsg+0x3c/0x5a
[ 822.340033] [<ffffffff8148f597>] ?
entry_SYSCALL_64_fastpath+0x12/0x6a
[ 822.340033] Code: 83 08 04 00 00 65 ff 00 48 8b 3c 24 e8 40 7c f2 ff
eb 13 48 c7 c3 9f ff ff ff eb 0f 89 ce e8 f1 ae f1 ff 48 89 c3 48 85 db
74 15 <48> 8b 83 08 04 00 00 65 ff 08 48 81 fb 00 f0 ff ff 76 0d eb 07
[ 822.340033] RIP [<ffffffff8148781e>] mpls_nh_assign_dev+0x10b/0x182
[ 822.340033] RSP <ffff88001dad7a88>
[ 822.340033] CR2: 00000000000003a3
[ 822.435363] ---[ end trace 98cc65e6f6b8bf11 ]---
After patch:
$ip -f mpls route add 100 as 200 via inet 10.1.1.8
RTNETLINK answers: Network is unreachable
Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Reported-by: David Miller <davem@davemloft.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
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